Radiopharmacy

Question 1

What are Radiopharmaceuticals?

Answer 1

Radioactive drugs which are administered to patients for:
- Diagnostic purposes
- Therapeutic purposes
Used for imaging or non-imaging
- Uses ionising radiation (Gamma, Beta, Alpha)

Question 2

Nuclear Decay: Alpha Decay

Answer 2

Not really used therapeutically as it is quite damaging

- Ejects a doubly charged Helium nucleus (He2+)

Question 3

Nuclear Decay: Beta Decay

Answer 3

Normally used for thyroid purposes, still damaging

• Excess neutrons gain stability by converting
• Neutron to Proton + Negatron (Nuclear electron/Beta particle)

Question 4

Nuclear Decay: Gamma

Answer 4

Most commonly used, they are photons and so does not cause the same damage as with beta and alpha decay
- No particles emitted only gamma photons

Question 5

Nuclear Medicine v X Rays

Answer 5

See separate sheet of paper

Question 6

Describe the Gamma Camera

Answer 6

Detects gamma radiation
Collimator
- Absorbs scatter to give clearer image
Sodium Iodide Crystal
Produces a light pulse
- When hit by gamma rays. The pulse of light is converted into an electric current which is sent to a computer an converted into data.

Question 7

What is 123 Iodine normally used for?

Answer 7

To diagnose under/over active thyroid glands

Question 8

What is 131 Iodine normally used for?

Answer 8

Not normally used clinically as the energy level is so high it would be damaging

Question 9

What is 111 Indium normally used for?

Answer 9

Used to radioactivity scan red or white blood cells

Question 10

What are the main characteristics of 99m Technetium?

Answer 10

Short half life
Gamma emitter
Low energy range
Decays to stable isotope
Combines with a wide range targeting tracers

Question 11

What are the key differences between aseptic services and radiopharmacy?

Answer 11

No prescription

Aseptic technique

• Operator safety first
• Time, distance, shielding

Legislation

• H&S Radiation Protection
• Environmental (Radioactive Substances Act)
• Transport (Radioactive Materials (Road Transport) Act)

Purchasing and contracts

Dose calculations and units of measure

• Patient doses in MBq
• Doses calculated for time of admistration (Half life)

QC
- Radiochemical purity, chromatography

Question 12

What are the additional roles of the Radiopharmacist?

Answer 12

Clinical pharmacy
- e.g. Adjuvant drugs
Drug information
- e.g. Breast feeding
Teaching and training
Research and development
Clinical trials

Question 13

MAG 3 is used for…

Answer 13

Kidney scans

- Investigate kidney function

Question 14

DMSA (Dimercaptosuccinic Acid) is used for…

Answer 14

Paediatric nephrology

• Function & renal outline
• Renal scarring

Question 15

How does a V/Q Lung scan work?

Answer 15

VENTILATION

• Inhale Krypton-81 gas
• Compare imagine with perfusion

PERFUSION

• Inject MAA
• Cold spots if no perfusion

Look for mismatch
- Diagnosis pulmonary embolisms

Question 16

What is Pertechnetate (TcO4) normally used for?

Answer 16

Thyroid imaging

• technetium has similar size and shape to iodine
• Stomach - Meckels diverticulum

Question 17

How is Organic phosphate complex commonly used?

Answer 17

• Homogenous distribution of tracer throughout skeleton
• Uptake by hydroxyapatite crystals
• Uptake dependent upon bone turnover
• Bone Metastases lead to areas of increased uptake in the skeeton as bone is replaced by tumour cells
• Eventually pathological fractures occur

Question 18

How are colloids commonly used?

Answer 18

Bone marrow and lymphatics

Standard Lymposcinitigraphy
Sentinel Node Localisation

Question 19

How is radioactive porridge normally used?

Answer 19

To calculate poo rate